Waterproof and fireproof fibrous product and process of making the same



Patented May 24; 1932 PATENT OFFICE UNITED STATES WILFORD BACON HOGGATT, OF NEW LONDON, CONNECTICUT warnnmoor ann mnnrnoor rnmous rnonuo'r'nnn PROCESS or MAKING THE No Drawing.

This invention relates to combined waterproof and fireproof fibrous products and a process of making the same.

The object of the invention is to producewhich are not only waterproof but are also non-inflammable or fireproof, but such efiorts have not been attended with any great de gree of success for the reason that the .materials essential for rendering the products F fire-resistant, and those for rendering it wator-resistant, when brought together react against each other and impair or destroy their respective fireproofing and waterproofing qualities. Moreover, the methods heretofore suggested for waterproofing and fireproofing the same body or product have been complicated and expensive and have failed to secure the desired degree of efiiciency of either the fireproofing or the waterproofing result.

It is among the special purposes of my present invention to provide a fibrous or pulp oard, panel or other product, and a process of preparing and making the same, which 1s not only simple and inexpensive, but in which the combined qualities of fireproofing and waterproofing are most efliciently attained.

In carrying out my invention I propose toemploy as the base material for the board, 40 panel or other product any suitable fibrous material, such as wood pulp, cotton linters, fabric, rags, paper, bagasse, cornstalks, or other pulp body of a cellulose fibre character.

This base material or pulp is formed in any, suitable or well known manner into a board,

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Application filed man 31, 1930. Serial No. 440,633.

panel or other desired product, and either while formlng the same into shape, or afterwards, or even whlle reducing the base material to pulp condition, I apply thereto the required chemicals or materials to render the same both fire-resistant and Water-resistant, I

according to the nature of pulp employed, and in such manner, and by the use of such materials as will enable the particles composing the fibrous body to be thoroughly impregnated with the fireproofing compound, throughout the entire body thereof, and the. impregnated particles to be covered or coated with a thin film of the waterproofing com pound employed, which does not injure or impair and, in turn, is-not injured or ima paired by the fireproofing compound.

) For securing the desired fireproofing quality of the fibrous board, panel or other product, I prefer to employ a solution containingborax, boracic acid, sulphate of ammonia, and a suitable glue, such as animal glue, ground or flaked, casein, soya bean glue, or the like.

For securing the desired waterproofing quality I propose to employ any suitable waterproofing compound or substance which is soluble in a volatile hydrocarbon such as gasoline, n aphtha, benzol, alcohol, or the like.

I have found a waterproofing material consisting of wax, either mineral or vegetable, such as paraflin, shale wax, beeswax, Montan I wax, or the like, or a combination of'resin and wax tailings efiicient for my purposes.

, It is important to employ a fibrous 'm'ateso rial for the base or body of the article to be produced, and also a fireproofing compound which will not be attacked or injured by the hydrocarbon solvent for the waterproofing.

compound. 5 In preparing the fireproofing compound, and by way of an illustrative example, I take 800 parts by weight of sulphate of ammonia having a nitrogen content of, say, 23% to 25%,200 parts of borax, 300 parts of borac1c v I acid, and 350 parts of the desired glue, animal or vegetable, as above stated. The glue is soaked in water, say for eight to twelve hours, or over night, and the ammonia, borax pounds of the chemicals used. The mass is then thoroughly stirred and mixed at a temperature suflicient to fuse the borax and boracic acid, say at a temperature of about 185? F., more or less. If desired, depending on the nature or character of the fibre employed for the base material the fireproofing compound, prepared as a ove explaned, may be diluted by adding water thereto.

l/Vhen the fibrous material, wood, fabric,

paper, bagasee, or the like, is reduced to the condition of pulp by grinding, in beaters, or otherwise, in the usual or well known way, the fireproofing compound, prepared as above described, may be employed in place of water or other liquid employed in connection with such grinding or beating. When applied and used in this manner the fireproofing compound becomes thorou hly incorporated into and throughout the %ody of the fibre base, and serves as a sizer therefor. The pulped material, whether pulped in the presence of the fireproofing compound or not is formed into a board,-sheet, panel, or other article to be produced, .in the usual or any Well known manner, and is then. dried. If

the pulping operation has been effected with the fireproofing compound, the salts of such compound become uniformly and thoro ughly distributed throughout the pulp body, and thoroughly impregnated therein so as to render such body non-inflammable when dried. Excessive temperatures should be avoided in drying the pulp body, the lowest possible drying temperature consistent with speed of output and commercial cost being used. I have found a drying temperature of approximately 180 F. or-, .higher gives good results.

By employing a comparatively low drying temperature the'fireproofing chemicals emfplloyed become more firmly adherent to the bre of the base body, the crystallization thereof is reduced to a finer de ee, and the glue content is less injured, an retains and imparts greater adhesiveness and hence greater homogeneity to the base body. The product should be removed from the drier as soon as the drying is completed.

While my invention contemplates and includes the 'pulping of the fibre in the fireproofing compound, and then drying, or partially drying the product, I prefer to first comminute or pulp the fibrous material with water and form it into a sheet or board, or other article and dry, or artially dry it, and then apply the fireproofing compound. this case the fireproofing compound-may be applied either by spraying the same onto the dried board, sheet or article, or impregnated face of the board or sheet is more or less' roughened but this is advantageous as it facilitates the penetration of the compound into the body of the fibre base. .As the moisture which is retained within the body of the base fibre tends to more or less dilute the fireproofing compond when impregnated into the body, it is preferable to remove more or less of the moisture of the body before spraying, dipping, or immersing the same with or in the compound. If the pulp sheet or board is formed in the usual way by means of vacuum or suction rolls, the application of the fireproofing compound may be effected at any desired point in the board or sheet forming operation, whether such application iseffected by spraying, dipping, or immersion, or by vacuumizing.

Where the fibrous material is pulped with the fireproofing compound any desired antifoaming agent or mixture may be employed. Kerosene is suitable for this purpose, but should be used sparingly in order to avoid damage or injury to the fibre or to the fireproofing quality of the compound.

After the board, sheet or other article has been completed and dried with the fireproofing compound impregnated therein, as above described, the waterproofing composition is then applied. This composition consisting of wax, either mineral or vegetable, such as parafiin, shale wax, Montan wax, beeswax, resin, wax tailings, or they like, dissolved in a-Jhydrocarbon solvent, such for example as gasoline, is exceedingly penetrating, not into the fibre particles themselves but around and in enveloping relation with respect to the I fibre particles to and into which the fireproofing compound has been applied. The hydrocarbon solvent for the waterproofing compound, however, does not attack nor mpair the fibre of the article for the reason that the fibre particles are already protected by the fireproofing material applied thereto which ticles of the body. a This depositing and film-,-

important feature of my invention asit secures a most efiicient waterproofing of a fireproofed fibrous body, a result which, so far as I am aware has never been successfully and satisfactorily accomplished in an economical manner. And in addition fixes the fireproofing chemicals in the body and prevents exudation of the fireproofing salts.

If desired the solvent for the waterproofing material may be recovered for use over again by condensing the vapors given off by the evaporation thereof.

If desired, and in order to increase the adhesion of the fibres in the board or other article, and to strengthen such article, alum or silicate of soda, or both, may be added to the mass during the pulping operation. I

Having now set forth the object and nature of my invention and the manner of carrying out the same, what I claim as new and useful and of my own invention is:

1. The method of making a fireproofed and waterproofed fibrous article which consists in pulping fibrous material and forming the same into the article to be produced impregnating such article with a fireproo ng compound, drying the article and finally penetrating the fireproofed article with a waterproofing material.

- 2. The method which consists in pulping suitable fibrous material and impregnating the same with a fireproofing compound, drying the fibrous material and finally deposlting a film of waterproofing material upon the surfaces of the fireproofed particles of fibrous material throughout the fibrous body.

3. The method which consists in pulping suitable fibrous material and impregnating the same with a fireproofing compound, drying said material and finally penetrating the body of the fireproofed fibrous material with a waterproofing compound carried in a volatile solvent, whereby a film of waterproofing material is applied to the surfaces of the partfilgof fibre of the body.

4. The method which consists in pulping suitable fibrous material and impregnating the same with a fireproofing compound, drying said material and finally penetrating the body of the fireproofed fibrous material with a waterproofing substance carried in a hyin gasoline, to deposit a film of waterproofing suitable fibrous material and impregnatlng the same with a fireproofing compound, drying the material and finally penetrating the body of the fireproofed fibrous material with a waterproofing substance carried in'solution material upon the surfaces of the fireproo fedfibrous particles throughout such body.

6; The method which consists in pulping suitable fibrous material and impregnating the same'with an aqueous compound of sulphate of ammonia, borax, boracic acid, and glue, drying the material and then penetrating the resulting body with a waterproofing material carried in a volatile solvent.

7. The method which consists in pulping suitable fibrous material and impregnating the same with an aqueous compound of sulphate of ammonia, borax, boracic acid, and glue, drying the material and then penetrating theresulting body with a waterproofing material carried in a hydrocarbon solvent.

8. The method which consists in pulping suitable fibrous material and impregnating the same with an aqueous compound of sulphate of ammonia, borax, boracic acid, and glue, drying the material and then penetrating the resulting body with a waterproofing material carried in gasoline.

9. The method which consists in pulping suitable fibrous material and impregnating thesame with an aqueous compound of sul-" phate of ammonia, borax, boracic acid, and glue, drying the material and then penetrating the resulting body with a wax dissolved in a volatile solvent.

10. The method which consists in pulping suitable fibrous material and impregnating the same with an aqueous compound of sulphate of ammonia, borax, boracic acid, and glue, drying the material and then penetrating the resultin body with a wax dissolved in a hydrocar on solvent.

11. The method which consists in pulping suitable fibrous material and impregnating the same with an aqueous compound of sulphate of ammonia, borax, boracic acid, and glue,- drying the material and then penetrating the resulting body with a wax dissolved in gasoline.

12. The method which consists in pulping suitable fibrous material and forming the same into a sheet, and drying it, then im-' 13. The method which consists in pulping suitable fibrous material and forming the same into a sheet, and drying it, then impregnating the sheet throughout with a fire proofing compound, drying the sheet again and finally penetrating the fireproofed sheet with awax.

14. The method which consists in pulping suitable fibrous material and forming the same into a sheet, and drying it, then impregnating the sheet throughout with a fireproofing compound, drying the sheet again and finally penetrating the fireproofed sheet with paraflin carried in a volatile solvent.-

15. The method which consists in'pulping suitable fibrous material and forming the same into a sheet, and drying it, then impregnating the sheet throughout with a fireproofing compound, drying the sheet again and finally penetrating the fireproofed sheet with parafiin dissolved in gasoline.

In testimony whereof I have hereunto set my hand on this 12th day of March, A. D.

YVILFORD BACON HOGGATT. 

